Automatic Colorant dispensers are well known in the art. Generally, colorant dispensed by these dispensers contains various abrasives and corrosive components including water. The prior art pumps used to dispense these colorants are of a lower quality, generic single impeller “oil-pump” type usually produced from cast iron and are continuously exposed to abrasive, oxidizing materials. These operating conditions cause dramatic wear to critical internal metering components in the generic prior art pumps resulting in their eminent failure usually within the first three months of normal system usage. These prior art pumps are very inconvenient to replace in existing prior art automatic colorant dispensers because of antiquated drive methods employed. These pumps are also very expensively priced and including the required qualified service technician labor, pump replacement can initially cost up to as much as one tenth of the total system price.
Prior art pumps were never originally designed to pump colorants. Prior art pumps handled many different types of oils. The oils provided the much needed shaft lubrication.
Because pumped colorants do not provide any lubrication, constant colorant abrasion under pressure attacks the solid cylindrical bearings needed to maintain the proper pump shaft rotational geometry in all prior art pumps. The prior art pump drive system torque requirements are extremely demanding, highly inefficient and drive up the overall electrical power requirements of the entire automatic colorant dispenser. A single prior art pump cannot be rotated manually indicating the extremely inefficient method of pump shaft bearing design.
Attempting to protect and to reduce the internal wear and damage caused by the hardened foreign matter in colorants, generic prior art pumps employ a ceramic plastic impeller. This material has proven to be a poor design choice for the application. Broken or chipped impeller teeth cause severe loss of calibration and reduce the pump output dramatically.
Prior art automatic dispenser manufacturers have also implemented individual colorant filters or strainer units attempting to protect their pumps from the foreign materials in the colorants. Because of the wide viscosity ranges of many popular colorants, the filters or strainers almost immediately clog up and starve their pumps of colorant. Because precise, repeatable metering is needed to deliver each colorant to achieve the desired color formula or recipe, the clogging causes the product to be mistinted and ultimately rejected.
Prior art dispensers usually contain from ten to sixteen colorant circuits each including one storage canister and one pump per colorant circuit. Prior art pumps are driven by either one or two ways.
The first method employs a large length of roller chain, associated idler sprockets to maintain chain positioning through the dispenser and a large horsepower motor with a gear reduction unit that provides the needed output power.
The second method is employing an individual motor of significant fractional horsepower with a combined gear reducer to an individual prior art pump with horizontal shaft rotation. The majority of prior art automatic dispenser manufacturers all have chosen the single roller chain driven approach over the large expense of multiple drive motor/gear reducers. Both of these drive approaches sacrifice individual precision metering because the prior art pumps were never designed to deliver dispense accuracies greater than {fraction (1/128)} of an ounce.
Replacement of pumps in the prior art has been difficult due to the pump locations and the critical realignment of these drive components must be completed in cramped confined space which is very time consuming. This intentionally reinforces that prior art pumps should only be replaced by factory approved service technicians.
Canisters of the prior art automatic dispensers have been produced from stainless steel tubes with welded bottom plates. Each colorant canister in a system contributes significant weight to the system. In configuring prior art automatic dispensers to dispense water-based colorants for architectural paints and coatings, stainless steel canisters provide no significant structural advantages and could actually be replaced with other equally compatible canister materials such as PVC (polyvinylchloride) that are lighter and more easily machined.
Automatic dispensers in the prior art utilize a discharge nozzle component that allows each individual colorant circuit to come together in a small diameter. The prior art nozzles have many mechanical joints where components must be connected at mating surfaces. O-rings are needed to seal each joint. Every joint is a potential location for colorant to leak between individual circuits causing cross contamination of all of the colorants.
Automatic dispensers in the prior art have been manufactured for over forty years using large, space consuming cabinets weighing in excess of a half ton with bulky roller conveyors attached to the front sections. Prior art cabinets were never efficiently designed for functional usage in providing adequate service access openings to critical internal components. Prior art dispenser manufacturers physically buried computers inside prior art cabinets eliminating the possibility of quick access or even simple upgrading of the operating PC system. For these types of customer service, an authorized factory technician would be required to perform these tasks.
For many years, the paint and coatings market has been requesting smaller, more compact cabinets to fit constantly shrinking floor space availability faced by paint retailers and manufacturers. Prior art manufacturers have responded to these requests only with automatic dispenser designs that suffer decreased performance and reliability to insure that their customer service departments maximized profitability.
Automatic dispensers in the prior art have always required the refilling of each of the colorant dispensers. Prior art manufacturers have made the colorant refilling process a difficult task by placing certain canisters in extremely hard to reach locations. In some models, half of the colorant canisters used are at the rear of the dispenser making access of those canisters impossible. Prior art dispensers have been poorly designed with the addition of heavy, hard to move roller conveyors that span the entire front of the dispenser cabinets.
Prior art manufacturers have not addressed the serious ergonomic needs of the operator for the safe operation and maintenance of prior art automatic dispensers. Operators place themselves in potentially harmful physical positions when attempting to reach the inaccessible rear mounted canisters. Operators must straddle the bulky, front mounted roller conveyor in the refilling process while pouring heavy containers of colorant at arms length.
Addressing the electrical requirements and associated electronics of existing automatic dispensers in the prior art have basically operated in the very same way for as long as they have been manufactured. Presently offered systems operate using inefficient large horsepower motors to handle the demanding torque requirements of each out of date pump. Safety is an issue when trying to replace or repair a component that may be near any one of the unguarded, exposed roller chain paths. It is important to note that these systems have not improved with modem cutting edge technology, either in mechanical advances or in innovative electronics.
Therefore, what is needed is a colorant pump that can withstand the abrasives and chemicals found in modern colorants, runs efficiently and with precision, and does not require a chain driven mechanism. A colorant dispenser is needed that includes an open cabinet architecture for easy and efficient cleaning and replacement of parts. A dispenser that contains a leak free and drip free nozzle is also needed.